President of the American Bach Society (2000-2004); President of the Internationale Arbeitsgemeinschaft für Hymnologie (1985-89); board of directors, Charles Wesley Society (1989-1999); Member of Scholarly Advisory Committee for the Kessler Reformation Collection, Pitts Theology Library, Emory University (1995-).

Author of more than 25 books, including Bachs theologische Bibliothek (1983), J.S. Bach and Scripture (1985), The Theological Character of Music in Worship (1989), "Goostly psalmes and spirituall songes": English and Dutch Metrical Psalters from Coverdale to Utenhove 1535-1566 (1991), Come to the Feast: The Original and Translated Hymns of Martin H. Franzman (1994) and (with Joyce Ann Zimmerman) Liturgy and Music: Lifetime Learning (1998).

Contributor to many reference and other books, including The New Grove Dictionary of Music and Musicians (1980, and the second edition, 2001), The New Grove Dictionary of American Music (1986), the 4th edition of The Harvard Dictionary of Music (2003), and The Hymnal 1982 Companion (1990-95).

Author of more than 200 articles and reviews in journals issued in England, Germany, the Netherlands, Africa, Korea, Japan, as well as the United States, including American Organist, Bach-Jahrbuch, Early Music, Choral Journal, Choral Review, MLA Notes, Musik und Kirche, Reformed Liturgy and Music, Worship, etc.

Editor of the series Studies in Liturgical Musicology (1994- ); co-editor of the series Drew Liturgical Studies (1996-2004); contributing editor to Jahrbuch für Liturgik und Hymnologie (1976-), The Hymnology Annual (1989-), and editorial consultant for liturgy and church music for the new edition of Die Religion in Geschichte und Gegenwart.

Active participant in national and international symposia including the Bach-Akademie, Stuttgart, Herzog August Bibliothek, Wolfenbüttel, The Newberry Library, Chicago, and the Royal Academy of Arts and Sciences, Amsterdam; and other institutions in Europe, Korea, Japan and New Zealand.

Author of program/liner notes and/or pre-concert lecturer for the Taverner Choir and Players, London; the Early Music Centre, London; the English Bach Festival, London; The Gabrieli Consort, England; The Bach Choir of Bethlehem, Pennsylvania; The Berkeley Festival, California; etc.; and for such conductors as Flummerfelt, Funfgeld, Leonhardt, McCreesh, Parrott, Shaw, among others.

Experienced in pastoral and church music ministries. Consultant to the British Broadcasting Corporation, London; Oxford University Press; and to the editorial committees that produced the Episcopal Hymnal 1982 (1985), The United Methodist Hymnal (1989), Evangelisches Gesangbuch (1993), and the Moravian Book of Worship (1995).

Listed in Contemporary Authors, Dictionary of International Biography, Who's Who in America, and similar reference works. Faculty, Latimer House, Oxford, England (1977-84); Wycliffe Hall, Oxford, England (1984-85); Visiting professor of liturgy, Drew University (1988-2002); Visiting professor of music history, The Juilliard School (2002- ). Westminster Choir College of Rider University (1984-).